I think you'll find limit orders limit the price while they're executing. Say I place a $10 million MSFT limit buy order at $80, that means that until my $10 million is used up (the order is "filled") the price cannot drop below $80.

Conversely if I place a $1B sell order for $1100 (ought to be close to what happened here) the price cannot rise above $1100 until that amount of money has been extracted out of the market.